1. Field of the Invention
The present invention relates to a device for packaging and dispensing fluid products, and more particularly a novel device for packaging and dispensing fluid, liquid or pasty products, of the type comprising at least two flexible bags placed in a single rigid container and connected to one or more pumps or valves, for the storage, protected from the air, of at least two fluid products and for dispensing them, as a mixture or separately, in an efficient manner.
2. Description of the Related Art
Devices of the pocket flask type for packaging and dispensing fluids are well known. They generally comprise a container with a rigid shell in which is placed a flexible bag that contracts as the product is extracted from it. The product may be expelled from the bag using an airless pump or under the pressure of a propellant gas acting within the flask, on the wall of the bag. When the product is expelled from the bag using an airless pump, a vent is provided, generally in the base or neck of the flask, to allow external air to enter the space between the flask and the bag each time the pump is actuated, thus allowing the bag to contract while maintaining sufficient pressure on its walls. An example of an embodiment using this method is described in patent FR 2 723 356 relating to a device comprising a flexible bag made of plastic, such as polyethylene or polypropylene, in a rigid container whose neck has an air inlet.
Another device using this method and designed for the selective dispensing of one or two products, separately or as a mixture, is described in patent FR 2 804 666, according to which a first product is introduced into the bag whereas the second, together with the propellant gas, are in the rigid container, around the bag, the whole being supplemented with a selective valve. However, this system is relatively complex and requires a special valve.
U.S. Pat. No. 5,411,176 describes a rigid container containing two flexible bags, in which the container is provided with a circular flange under which are fastened two bags inserted through the flask's removable base, and bearing two airless pumps. Another device comprising a rigid container associated with two bags and two valves is described in utility model DE-91 05 565 in which the bags are fastened via tubular sleeves and connecting tubes to a plate housing the valves.
The problems with this method are often linked to the deformations in the wall of the bag as it contracts, which can hold back considerable amounts of product and limit the efficiency with which the fluid is dispensed. Another problem is to ensure satisfactory sealing of the bag so as to preserve the integrity of the product contained therein. Specifically, the products contained in the bags are often sensitive to oxidation caused by oxygen in the air and can deteriorate if air enters the bag. Sealing defects are often found at the junction between the bag and the pump. They can also result from a degree of porosity of the materials used to make the bag. Lastly, the folds formed by the wall of the bag as it contracts can lead to tears that can let air in which degrades the product contained in the bag.
These problems are exacerbated when it is desired to use two or more bags within the same rigid container to dispense, simultaneously or separately, two or more complementary products.